sound

　　When they were talking in the room, the bell sounded.

　　When I saw the smoke, I tried to sound the alarm.

　　My father is a person of sound judgment.

　　The baby is sound asleep now.

　　sound在教材中的第一个意思为听起来,作动词用;第二个意思为声音,作名词用。在上面的四个句子中,前两个sound作动词用,意思分别为(使)发出声音,响和鸣警报第三个sound作形容词用,意思为明智的第四个sound作副词用,意思为酣,沉。